The present invention is related to digger derrick core barrels such as those made by Terex Utilities.
Some core barrels have been outfitted with central pilot bits. While these core barrels with pilot bits have enjoyed considerable success in the industry, they do have some drawbacks. In some applications, it may be desirable to use the pilot bit at the early stages of boring a hole and not at later stages. In such cases, it has been known to stop the drilling process to remove the core barrel, with pilot bit attached, from the partially dug hole in the ground and then remove the pilot bit and resume drilling. This process takes time, requires the presence of a person who is skilled enough to remove the pilot bit, and requires a storage place for the pilot bit.
Consequently, there is a need for improvement in core barrels with pilot bits.